Modeling compressive strength of cement asphalt composite based on pore size distribution

Cement asphalt composite is a porous material with various connected and closed pores, and pore structure is the major factor affecting its strength. In this paper, the pore structure of cement asphalt composites with different asphalt contents were analyzed by the combination of Nuclear Magnetic Resonance (NMR) and modified image analysis methods. The former one mainly detects the smaller and open pores, and the latter one mainly measures the larger and spherical closed pores. The total porosity is the sum of open and closed porosities. A model, based on Griffith theory and complete pore structure, was developed to predict the compressive strength of cement asphalt composites with high and low asphalt contents. It is demonstrated that the proposed models predict the compressive strength of cement and asphalt composite quite well.